diff options
| -rw-r--r-- | arch/powerpc/platforms/pseries/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/platforms/pseries/cmm.c | 133 | ||||
| -rw-r--r-- | include/uapi/linux/magic.h | 1 |
3 files changed, 121 insertions, 14 deletions
diff --git a/arch/powerpc/platforms/pseries/Kconfig b/arch/powerpc/platforms/pseries/Kconfig index 9e35cddddf73..595e9f8a6539 100644 --- a/arch/powerpc/platforms/pseries/Kconfig +++ b/arch/powerpc/platforms/pseries/Kconfig @@ -108,6 +108,7 @@ config PPC_SMLPAR config CMM tristate "Collaborative memory management" depends on PPC_SMLPAR + select MEMORY_BALLOON default y help Select this option, if you want to enable the kernel interface diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c index 3a55dd1fdd39..0663ddad964a 100644 --- a/arch/powerpc/platforms/pseries/cmm.c +++ b/arch/powerpc/platforms/pseries/cmm.c @@ -19,6 +19,10 @@ #include <linux/stringify.h> #include <linux/swap.h> #include <linux/device.h> +#include <linux/mount.h> +#include <linux/pseudo_fs.h> +#include <linux/magic.h> +#include <linux/balloon_compaction.h> #include <asm/firmware.h> #include <asm/hvcall.h> #include <asm/mmu.h> @@ -77,13 +81,11 @@ static atomic_long_t loaned_pages; static unsigned long loaned_pages_target; static unsigned long oom_freed_pages; -static LIST_HEAD(cmm_page_list); -static DEFINE_SPINLOCK(cmm_lock); - static DEFINE_MUTEX(hotplug_mutex); static int hotplug_occurred; /* protected by the hotplug mutex */ static struct task_struct *cmm_thread_ptr; +static struct balloon_dev_info b_dev_info; static long plpar_page_set_loaned(struct page *page) { @@ -149,19 +151,16 @@ static long cmm_alloc_pages(long nr) __GFP_NOMEMALLOC); if (!page) break; - spin_lock(&cmm_lock); rc = plpar_page_set_loaned(page); if (rc) { pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc); - spin_unlock(&cmm_lock); __free_page(page); break; } - list_add(&page->lru, &cmm_page_list); + balloon_page_enqueue(&b_dev_info, page); atomic_long_inc(&loaned_pages); adjust_managed_page_count(page, -1); - spin_unlock(&cmm_lock); nr--; } @@ -178,21 +177,19 @@ static long cmm_alloc_pages(long nr) **/ static long cmm_free_pages(long nr) { - struct page *page, *tmp; + struct page *page; cmm_dbg("Begin free of %ld pages.\n", nr); - spin_lock(&cmm_lock); - list_for_each_entry_safe(page, tmp, &cmm_page_list, lru) { - if (!nr) + while (nr) { + page = balloon_page_dequeue(&b_dev_info); + if (!page) break; plpar_page_set_active(page); - list_del(&page->lru); adjust_managed_page_count(page, 1); __free_page(page); atomic_long_dec(&loaned_pages); nr--; } - spin_unlock(&cmm_lock); cmm_dbg("End request with %ld pages unfulfilled\n", nr); return nr; } @@ -484,6 +481,106 @@ static struct notifier_block cmm_mem_nb = { .priority = CMM_MEM_HOTPLUG_PRI }; +#ifdef CONFIG_BALLOON_COMPACTION +static struct vfsmount *balloon_mnt; + +static int cmm_init_fs_context(struct fs_context *fc) +{ + return init_pseudo(fc, PPC_CMM_MAGIC) ? 0 : -ENOMEM; +} + +static struct file_system_type balloon_fs = { + .name = "ppc-cmm", + .init_fs_context = cmm_init_fs_context, + .kill_sb = kill_anon_super, +}; + +static int cmm_migratepage(struct balloon_dev_info *b_dev_info, + struct page *newpage, struct page *page, + enum migrate_mode mode) +{ + unsigned long flags; + + /* + * loan/"inflate" the newpage first. + * + * We might race against the cmm_thread who might discover after our + * loan request that another page is to be unloaned. However, once + * the cmm_thread runs again later, this error will automatically + * be corrected. + */ + if (plpar_page_set_loaned(newpage)) { + /* Unlikely, but possible. Tell the caller not to retry now. */ + pr_err_ratelimited("%s: Cannot set page to loaned.", __func__); + return -EBUSY; + } + + /* balloon page list reference */ + get_page(newpage); + + spin_lock_irqsave(&b_dev_info->pages_lock, flags); + balloon_page_insert(b_dev_info, newpage); + balloon_page_delete(page); + b_dev_info->isolated_pages--; + spin_unlock_irqrestore(&b_dev_info->pages_lock, flags); + + /* + * activate/"deflate" the old page. We ignore any errors just like the + * other callers. + */ + plpar_page_set_active(page); + + /* balloon page list reference */ + put_page(page); + + return MIGRATEPAGE_SUCCESS; +} + +static int cmm_balloon_compaction_init(void) +{ + int rc; + + balloon_devinfo_init(&b_dev_info); + b_dev_info.migratepage = cmm_migratepage; + + balloon_mnt = kern_mount(&balloon_fs); + if (IS_ERR(balloon_mnt)) { + rc = PTR_ERR(balloon_mnt); + balloon_mnt = NULL; + return rc; + } + + b_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb); + if (IS_ERR(b_dev_info.inode)) { + rc = PTR_ERR(b_dev_info.inode); + b_dev_info.inode = NULL; + kern_unmount(balloon_mnt); + balloon_mnt = NULL; + return rc; + } + + b_dev_info.inode->i_mapping->a_ops = &balloon_aops; + return 0; +} +static void cmm_balloon_compaction_deinit(void) +{ + if (b_dev_info.inode) + iput(b_dev_info.inode); + b_dev_info.inode = NULL; + kern_unmount(balloon_mnt); + balloon_mnt = NULL; +} +#else /* CONFIG_BALLOON_COMPACTION */ +static int cmm_balloon_compaction_init(void) +{ + return 0; +} + +static void cmm_balloon_compaction_deinit(void) +{ +} +#endif /* CONFIG_BALLOON_COMPACTION */ + /** * cmm_init - Module initialization * @@ -497,9 +594,14 @@ static int cmm_init(void) if (!firmware_has_feature(FW_FEATURE_CMO)) return -EOPNOTSUPP; - if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0) + rc = cmm_balloon_compaction_init(); + if (rc) return rc; + rc = register_oom_notifier(&cmm_oom_nb); + if (rc < 0) + goto out_balloon_compaction; + if ((rc = register_reboot_notifier(&cmm_reboot_nb))) goto out_oom_notifier; @@ -527,6 +629,8 @@ out_reboot_notifier: unregister_reboot_notifier(&cmm_reboot_nb); out_oom_notifier: unregister_oom_notifier(&cmm_oom_nb); +out_balloon_compaction: + cmm_balloon_compaction_deinit(); return rc; } @@ -545,6 +649,7 @@ static void cmm_exit(void) unregister_memory_notifier(&cmm_mem_nb); cmm_free_pages(atomic_long_read(&loaned_pages)); cmm_unregister_sysfs(&cmm_dev); + cmm_balloon_compaction_deinit(); } /** diff --git a/include/uapi/linux/magic.h b/include/uapi/linux/magic.h index 903cc2d2750b..3ac436376d79 100644 --- a/include/uapi/linux/magic.h +++ b/include/uapi/linux/magic.h @@ -94,5 +94,6 @@ #define ZSMALLOC_MAGIC 0x58295829 #define DMA_BUF_MAGIC 0x444d4142 /* "DMAB" */ #define Z3FOLD_MAGIC 0x33 +#define PPC_CMM_MAGIC 0xc7571590 #endif /* __LINUX_MAGIC_H__ */ |